Why Is This Pond Here? EarthCache

This pond is one of approximately 200 locations in the City of London that has been built to help keep the local rivers and streams cleaner than they would be if this pond was not here. This pond is one of many Detention Ponds or Retention Ponds built by the city or private developers which play a major role in controlling the effects of stormwater on the environment.

The majority of new regional SWM systems in London are represented by wet ponds. However, the City’s Storm Water Management infrastructure constructed in the 1980s and the early 1990s include a number of surface storage areas, dry ponds, wet channels, oversized pipes, and oil/grit separators.

;A storm water management pond is an artificial pond  which is designed to  collect and hold stormwater. There are two types of storm water ponds, Retention Ponds and Detention Ponds. They may look similar but there are differences between the two types of ponds. The true purpose of these ponds is not for recreational purposes, though they are often accessible to the public and may have walkways and occasionally a hiking trail nearby. You may also see a ramp at these ponds but the ramp is not there for use of the public for recreational purposes. The ramp is only for use by city staff for maintenance purposes or possibly for use by emergency personnel.

<p>Storm water management ponds serve a very important purpose. During rains and particularly storms the water that makes its way to storm sewers  from streets, parking lots, lawns, fields, etc. will become contaminated with oil, soap, fertilizers and any other matter including fecal matter from animals which the run-off comes in contact. In the built up areas of larger towns and cities in particular the ground cannot absorb the large amounts of water thus the sotrm sewers receive large quantities of contaminated run-off. This run-off is directed to the numerous storm water ponds where it may be held or directed to one of several water treatment plants thus this water is treated before it makes its way to the natural waterways, if directed to a Retention Pond or held at a pond if the pond is a Detention Pond.

<p>A Detention Pond is a 'dry pond' in a low lying area that temporarily holds water until the water drains to another location. A detention pond is typically used for storm control when large amounts of rain or storms will produce excessive run-off which could produce flash flooding.

<p>A Retention Pond is a pond which will hold a specific amount of water indefinitely. The pond will have drainage outlets leading to another location to keep the pond from overflowing during heavy rains; but the pond will be designed to hold water at all times.. A retention pond will have fluctuating water levels from month to month but the pond has been designed to  standards which will prevent flooding.

<p> In addition to the basin of the pond both types of ponds may have certain types of vegetation which also assists the environment. Grasses, trees and shrubs provide stability for the banks of the ponds; and aquatic vegetation  helps the water quality by removing soluble nutrients; as well as also improving the diversity of animals in the area.

<p> 1. During your visit was the water level high, moderate or low based on nature's markers? 

<p> 2. Why do you think the water level in this pond is at the level you observed during your visit?

<p> 3. Is this pond a Detention Pond or a Retention Pond? Give reasons for your answer?

<p> Please give a few examples of vegetation in the area as well as the animals you saw during your visit.

www.london.ca/residents/Sewers-Flooding/stormwater/Pages/Stormwater-Management-Facili